rustc_queries!: Don't push the (cache) modifier twice

Author: Zalathar

compiler/rustc_macros/src/query.rs

@@ -378,9 +378,6 @@ pub(super) fn rustc_queries(input: TokenStream) -> TokenStream {
             return_result_from_ensure_ok,
         );
 
-        if modifiers.cache.is_some() {
-            attributes.push(quote! { (cache) });
-        }
         // Pass on the cache modifier
         if modifiers.cache.is_some() {
             attributes.push(quote! { (cache) });